This application is related to and claims priority from Japanese Patent Application No. 2000-256889, incorporated herein by reference.
1. Field of the Invention
The present invention relates to a weather strip for sealing an opening portion around an opening in a vehicle body against a periphery of a closing member for closing the opening in the vehicle body.
2. Description of Related Art
To seal an opening portion of a vehicle body around an opening such as a door opening or trunk lid opening against a periphery of a closing member such as a door or trunk lid, weather strips are attached to the opening portion of the vehicle body and/or the periphery of the closing member.
As illustrated in FIG. 1, a door opening 10 which is formed in a side portion of a vehicle body is opened and closed by a rear slide door 12. A weather strip (not shown) is attached to a flange (not shown) formed around the door opening 10.
As illustrated in FIG. 2 which is taken along the line Cxe2x80x94C of FIG. 1, a weather strip 14 includes a base portion 16 having a generally U-shaped cross-section, and a tubular seal portion 18 which projects outwardly from an outer side wall of the base portion 16. The base portion 16 is attached to a flange 20 projecting into the door opening 10.
Upon closing the door opening 10, the slide door 12 is slid from its open position along the rear side of the vehicle body toward its closed position. And just before the door opening 10 is closed, the slide door 12 is guided by a guide member provided along a lower side of the door opening 10 and is shifted inwardly into flash with the rear side of the vehicle body. At this time, an inside face of a periphery of the slide door 12 contacts and presses the seal portion 18.
The base portion 16 of the weather strip 14 is generally composed of a solid EPDM rubber or solid thermoplastic olefin elastomer (TPO), and the seal portion 18 which projects into an arc-shaped cross-section is generally composed of a sponge EPDM rubber or sponge TPO. A metal core 22 is embedded in the base portion 16.
If the seal portion 18 is entirely composed of a sponge material, the seal portion 18 is irregularly deformed because of its insufficient rigidity when the slide door 12 presses the seal portion 18. Consequently, the sealing properties of the seal portion 18 become instable. To overcome this problem, root parts of the seal portion 18 have been composed of a solid material integrally with the base portion 16.
When the weather strip 14 thus arranged is extruded integrally, the position of boundaries 24 and 26 between solid parts and sponge parts in the seal portion 18 inevitably scatters. Where the boundaries 24 and 26 are positioned too low relative to the seal portion 18, the seal portion 18 may be deformed irregularly when the slide door 12 presses the seal portion 18. On the other hand, where they are positioned too high relative to the seal portion 18, the solid root parts of the seal portion 18 exert a large counterforce against the slide door 12 upon closing the door opening 10. Consequently, a large force is required to close the slide door 12 with the result that the slide door 12 strikes on the seal portion 18 strongly, which is less preferable. In addition, the position of the boundaries 24 and 26 also inevitably scatters in the longitudinal direction of the weather strip 14, whereby the sealing pressure of the weather strip 14 may become nonuniform locally.
Accordingly, it is an object of the present invention to provide a weather strip capable of keeping stability of a seal portion despite scattering in the position of boundaries between solid parts and sponge parts therein, and effecting a uniform sealing pressure over an entire length of the seal portion while preventing a closing member from strongly striking on the seal portion upon closing an opening in a vehicle body.
The weather strip in accordance with the present invention includes a base portion, and a tubular seal portion which projects outwardly from an outer surface of the base portion. The seal portion includes a pair of leg portions, each projecting outwardly from the outer surface of an outer side wall of the base portion, extending portions which extend from ends of the leg portions in opposite directions along the outer side wall to have an L-shaped cross-section with the leg portion, and a seal wall for connecting ends of the extending portions into an arc-shaped cross-section. The base portion and the leg portions are integrally composed of a solid rubber-like resilient material while the seal wall is composed of a sponge rubber-like resilient material. A boundary between the solid rubber-like resilient material and the sponge rubber-like resilient material is located in each of the extending portions of the seal portion.
The extending portions are arranged so as to extend in approximately parallel to a seal face of a closing member such as a slide door, which is in its closed position. Since the boundaries between solid parts and sponge parts are located in the extending portions, scattering in the position of the boundaries scarcely affects the sealing pressure of the seal wall. Furthermore, where the seal face of the closing member largely presses the seal wall of the weather strip upon closing the opening in the vehicle body, the extending portions flex at about corners between the extending portions and the leg portions to release a counterforce which would be exerted by the solid parts against the seal face of the closing member. In addition, where the seal face of the closing member presses the seal wall obliquely, the extending portions including the solid parts retain their shapes thereagainst to prevent the seal wall from entirely falling down toward the base portion.
Other objects, features, and characteristics of the present invention will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification.